OBJECTIVE:
To assess the food intake and the nutritional status of children on a cow's
milk and cow's milk by-products free diet.METHODS: Twenty-six children receiving a cow's milk and cow's milk by-products
free diet were assessed during their first visit to the Pediatric Gastroenterology
Clinic (mean age = 19.1 months). Thirty children with no food restriction (mean
age = 16.8 months) were also assessed. The usual daily food intake method was
used to make the dietary assessment. The food intake was compared between the
groups and in relation to the Dietary Reference Intakes (DRIs). The z-scores
for weight/age, height/age and weight/height were used to evaluate the nutritional
status.RESULTS: The cow's milk free diet group presented lower energy (p = 0.005),
protein (p < 0.001), lipid (p < 0.001), calcium (p < 0.001) and phosphorous
(p < 0.001) intake when compared to the control group. The number of children
who had energy, calcium and phosphorous intake below the DRIs was higher in
the cow's milk free diet group than in the control group. The z-score means
for the cow's milk free diet and control groups were, respectively: height/age
-0.81±1.06 vs +0.42±1.25 (p < 0.001), weight/age -1.03±1.21
vs +0.02+0.91 (p < 0.001), and weight/height -0.63+1.08
vs +0.30+1.11 (p = 0.004).CONCLUSIONS: During the cow's milk and cow's milk by-products exclusion
therapy, qualitative and quantitative food intake monitoring must be carried
out periodically, so as to prevent inadequacies in meeting nutritional requirements
and impairment of growth and development.

Intolerance and
allergies to cow's milk predominantly occur during the first 3 years of life.
Treatment is based on excluding cow's milk, an important source of nutrients
for children on artificial feeding, from the diet.1

Care should be
taken to introduce an adequate substitute diet which meets the child's nutritional
needs when employing this therapy.2 Some studies have demonstrated
reduced ingestion of some nutrients,1,3 in addition to reduced stature3,4
in children on a cow's-milk-free diet when compared to children on a normal
diet.

The elimination
of cow's milk and cow's milk by-products from the diet could lead to insufficient
calcium ingestion1,3,5,6  an element fundamental to bone health7
 increasing the risks of bone mineralization problems8 Cases
of rickets,9 osteopenia and osteoporosis have been described in association
with low calcium ingestion over long periods as a result of the elimination
of cow's milk and cow's milk by-products from the diet.10

This being said,
even in situations in which the elimination diet is recommended as a therapeutic
test, nutrient intake and nutritional status assessment is necessary so that
possible inadequacies can be detected and corrected.11

The objective
of the current study was to evaluate the consumption of nutrients and the nutritional
status of children on a diet free from cow's milk and cow's milk by-products
in comparison with a group of children, from the same age group and socio-economic
level, on a normal diet.

Methods

This is a cross-sectional
study in which two groups were compared: one on a diet free from cow's milk
and cow's milk by-products and the other on a normal diet, i.e. with no medical
or therapeutic recommendation to exclude any given food.

A total of 26
children were evaluated, 11 female, 15 male and with a mean age of 19.1 months.
All of them had been prescribed a diet free from cow's milk and cow's milk by-products
at their first consultation at the Pediatric Gastroenterology Clinic of the
Universidade Federal de São Paulo - Escola Paulista de Medicina,
during the period between September 2001 and April 2002.

The control group
was made up of 30 children, of whom 13 were female and 17 were male, with a
mean age of 16.8 months and on normal diet, seen consecutively at the Childcare
Clinic of the Jardim Santo Eduardo basic health center, in the municipality
of Embu.

Elimination criteria
for both groups were: fulltime attendance at a school or day-care center, maternal
difficulty filling out the questionnaire on the child's nutrition, consumption
of human milk and refusal to participate in the study.

Weight and stature
were measured according to recommendations made by Jellife.12 The
anthropometric indices employed were z scores for weight/age (W/A), stature/age
(S/A) and weight/stature (W/S). In line with World Health Organization recommendations
nutritional deficiency was defined as a z score below 2.0 standard deviations.13
The z scores were calculated with the aid of Epi Info version 6.0 which employs
the NCHS - National Center for Health Statistics data on weight and stature
as its reference norms.14,15

The usual daily
diet method was employed with the objective of defining the usual dietary consumption
of the child.16,17 During the interview questions were asked about
meal times, foods and preparations consumed in addition to the six of the portions
consumed during a typical dietary day. In order to define portion sizes photographic
records18 and models of utensils (cups, cutlery, plates, babies'
bottles) were used. Calculations were performed with the aid of the Sistema
de Apoio a Decisão em Nutrição (Nutritional Decision
Support System) version 2.5 computer program.19 Nutrient intake was
compared between the two groups (children on a diet free from cow's milk and
cow's milk by-products and the controls) and also in relation to the National
Research Council recommendations, as described in the Dietary References Intakes
(DRIs) document.20-23

A standardized
questionnaire was administered to both the group on a cow's milk and cow's milk
by-products free diet and the control group in order to obtain the following
data:

 family
income: number of national minimum salaries/month;

 vitamin
supplement usage: brand and daily supplement dose;

 duration
of exclusive maternal breastfeeding defined as when the child receives only
breastmilk and no other liquid or solid with the exception of vitamins, minerals
and/or medicines in the form of drops or syrups, in accordance with the World
Health Organization.24

For the group
on a diet free from cow's milk and cow's milk by-products, in addition to the
information already described, the following were also recorded: duration of
elimination diet, any other foods excluded and the clinical manifestations that
prompted the cow's milk and cow's milk by-products free diet to be prescribed.

Parametric and
no parametric tests were used to analyze the results depending on the nature
of the variables being studied. Fisher's exact test and the chi-square test
were used to compare observed proportions for the two independent groups, i.e.
children in the experimental group and the control group. The comparison between
continuous variables for the two groups, two independent samples, was performed
using the Mann-Whitney tests. The Kruskal-Wallis test and Dunn's multiple comparison
test were applied to the analysis of four independent samples for the assessment
of calcium. Calculations were performed using the program SigmaStat.25
The cut off for rejection of the null hypothesis was set at = 0.05 or 5%.

Sample size was
estimated based on the expectation of insufficient calcium consumption among
children on cow's milk and cow's milk by-products free diets. In a similar study
in England, 60% of children on a diet free from cow's milk and cow's milk by-products
were found to have calcium ingestion below 75% of the standard adopted as parameter,
while among those children on normal diets this percentage was 17%.6
The sample size was therefore calculated taking the difference between groups
as 43%, a error < 0.05 and statistical power of 80%, thus giving a minimum
of 24 individuals in each group.25

The experiment
was approved by the Committee for Ethics in Research at the Universidade
Federal de São Paulo/Hospital São Paulo. Informed consent
was obtained in writing from legal guardians.

Results

The clinical manifestations
that prompted the free from cow's milk and cow's milk by-products, due to clinical
suspicion of allergy or intolerance to this food were: failure to thrive (nine),
diarrhea (seven), vomiting or regurgitation (six), blood in feces (six), chronic
intestinal constipation (five), dermatitis (five), gastroesophageal reflux (three),
bronchitis or wheezing (three). Nine of the patients, 34.6%, presented just
one of the clinical manifestations listed, while 57.7% (15/26) exhibited two
and 7.7% (two) three or more manifestations.

For the group
on cow's milk and cow's milk by-products free diets, the medians (25th and 75th
percentiles in parentheses) for age at start of diet and duration of diet were,
9.0 months (4.0-14.1) and 7 months (2.0-13.5) respectively. Foods excluded from
diets were as follows:

General characteristics
and anthropometric indices for the two groups are shown in Table
1. Observe that, for all indices, the group on diets free from cow's milk
and cow's milk by-products presented mean z scores lower than did the control
group, with these differences being statistically significant. Taking individual
z score values and a < -2.0 standard deviations cut-off point, the group
on cow's milk and cow's milk by-products presented a greater number of children
with deficiencies compared with the control group for all indices, although
the difference was only statistically significant for the weight/age index (Table
2).

The group on diets
free from cow's milk and cow's milk by-products presented reduced ingestion
of energy, proteins and lipids compared with the control group, which differences
were statistically significant (Table 3).

Of the 26 children
on cow's milk and cow's milk by-products free diets, 10 (38.5%) were given a
soy-based formula and two (7.7%) formula based on hydrolyzed proteins, while
the remainder did not receive any cow's milk substitute formula. With respect
of nutritional supplements, it was observed that in the group on the cow's milk
diet, nine (34.6%) children used a calcium supplement, nine (34.6%) iron supplement,
seven (26.9%) vitamin A supplement, eight (30.7%) vitamin D and three (11.5%)
vitamin C supplement. It was observed that, of the 30 children in the control
group, six (20%) used iron supplement, 15 (50%) vitamin A supplement, 15 (50%)
vitamin D supplement and six (20%) vitamin C supplement.

Table
4 presents the median ingestion of calcium, phosphorous, iron and vitamins
A, C and D for the two groups, broken down into the contribution made by foods
(including formulae) and, separately, the contribution made by foods summed
to that made by vitamin and mineral supplements.

The median calcium
and phosphorous intake was significantly greater in the control group. Even
when the contribution made by calcium supplementation was taken into account,
the calcium intake for the group on diets free from cow's milk and cow's milk
by-products presented as diminished. Similar iron consumption was observed for
the children on cow's milk and cow's milk by-products free diet and the controls,
although when the contribution of foods was summed with that of supplements,
intake was greater among the children on diets free from cow's milk and cow's
milk by-products than among controls, due to the fact that a proportion of the
patients were receiving oral iron therapy (Table 4).

The control group
exhibited greater vitamin A consumption, both when dietary contribution was
taken in isolation and when it was added to the supplementary contribution,
although the observed difference was only statistically significant in the first
case (dietary contribution). Vitamin C intake was higher in the group of children
on cow's milk and cow's milk by-products free diets, differing significantly
from that of the control group (Table 4).

The group of children
on diets free from cow's milk and cow's milk by-products were split into three
subsets in order to verify calcium consumption: children on formula (12), children
using calcium supplementation (seven) and children receiving neither formula
nor calcium supplement (seven). Their median calcium intakes were (25th and
75th percentiles in parentheses) were 665.90 mg/day (506.08-837), 423.83 mg/day
(215.60-657.13) and 158.82 mg/day (79.67-211.25), respectively. The same value
for the control group was 1,017.59 mg/day (739.43-1,210.68). Median calcium
intake was analyzed across the four groups with the Kruskal-Wallis test, which
indicated statistically significant differences. It was found that children
who had received calcium supplementation and those who had received neither
supplementation or formula exhibited lower calcium intake than did the control
group, according to Dunn's multiple comparison test (p < 0.05), while the
group that had received formula did not present a statistically significant
difference in comparison with the control group.

Energy and nutrient
intake for both groups was compared with the Dietary Reference Intakes, and
it was observed that a number of children in each group failed to reach 100%
of the recommended levels (Table 5). Observe, in Table
6, that the group on cow's milk free diets has the greatest number of children
with intakes below recommended levels for energy, calcium, phosphorous and vitamin
D, indicting that formula contributes significantly to the nutrient intake of
these children.

Discussion

The results allow
us to state that the nutrition of these children on diets free from cow's milk
and cow's milk by-products presents nutrient deficiencies, in particular in
terms of energy and calcium, in relation both to international recommendations
and to the control group. It is important to emphasize that, as Table
1 shows, there were no differences between the groups in terms of the distribution
of family income, sex, age or prior exclusive natural breastfeeding.

Our study is similar
to four experiments performed in Europe, which evaluated the dietary intake
of children on diets free from cow's milk with an average age of around two
years.1,3-5

The nutrient intake
of 16 Norwegian children on cow's milk and cow's milk by-products free diets,
was compared with that of children receiving soy or hydrolyzed protein based
formulae (n = 6), children who weren't receiving formula (n = 10) and controls
(children on diets excluding eggs, but not milk or cow's milk by-products; n
= 10). When the groups were compared, the formula was observed to make an important
contribution to adequate energy and macronutrient intake. Notwithstanding, calcium
intake was lower among children on elimination diets than in the control group,
irrespective of the use of formula, which fact is possibly the result of the
lower volume of formula ingested by children on the elimination diet when compared
with the controls.1

Another study
evaluated 19 Finnish children on a diet excluding multiple foods, including
cow's milk and cow's milk by-products. Just two of the 19 children were receiving
formula and the remainder used calcium supplementation. There were no differences
in terms of energy, lipid or carbohydrate intake between the children on elimination
diets and the controls. The children on elimination diets did, however, exhibit
reduced consumption of protein, phosphorous, magnesium, zinc and calcium.3

Another study
performed in Finland assessed 18 children on cow's milk and cow's milk by-products
free diets (13 receiving formula and 17 calcium supplementation). No important
differences were detected between the nutrient intake of this group of children
in comparison with controls, but it was ascertained that formula use did not
ensure adequate calcium intake, although, with the use of concurrent calcium
supplementation, the children on elimination diets' intake became comparable
to that of the control group.4

In England, 23
children on diets excluding multiple foods, 12 of whom received soy or hydrolyzed
protein formula, did not exhibit important differences in dietary intake when
compared to a control group, with the exception of calcium consumption, which
was lower for the group on elimination diets.5

In our experiment,
in contrast with what was observed in some of the papers cited,3-5
energy intake was considerably lower among the group on elimination diets. The
patients also consumed a statistically significant quantity less of proteins
and lipids. This suggests that the group had lower food intake in general and
not a deficiency of any particular macronutrient.

The use of formula
as a substitute for cow's milk during an elimination diet is a feature that
merits attention. The formulae usually used are based on hydrolyzed proteins
or soy and represent an important contribution to nutrient ingestion, particularly
for infants and small children, taking into consideration the difficulties involved
with this age group in substituting cow's milk entirely with solid foods.4
Notwithstanding, it is important to assess formula daily intake, observing level
of dilution and volume offered, since some studies have found that the volume
of formula consumed daily by children on diets free from cow's milk and cow's
milk by-products is significantly lower than the milk intake of children on
normal diets,1,4 and in our country there is one further aggravating
factor which is the high cost of formulae which could lead to incorrect dilution
and/or the offer of insufficient quantities.

Another important
factor is the use of soy-based drinks or juices as a substitute for cow's milk.
Two of the children on diets free from cow's milk and cow's milk by-products
in our study consumed soy-based juice with a low calcium content that does not
meet the Dietary Reference Intakes recommendation for calcium.20
There are three case histories in the literature describing rickets in Belgian
children aged between 15 and 18 months associated with calcium deficiency resulting
from the use of a soy-based drink.26 This type of product is not
specifically formulated for the pediatric age group and as such should not be
recommended as a substitute for cow's milk.

During a diet
excluding cow's milk and cow's milk by-products, a large proportion of daily
intake can be supplied by means of supplementation, which should be sufficient
to meet the adopted recommendation. The calcium intake level recommended by
the Dietary Reference Intakes varies according to age group: 210 mg/day (0 to
6 months), 270 mg/day (7 to 12 months) and 500 mg/day (13 to 36 months).20
Our results demonstrated calcium intake below these levels even when supplementation
had been instituted (Table 4). The difficulty in correctly
prescribing calcium supplementation may be a result of the existence of many
different calcium formulations on the market. The choice of calcium supplement
will depend upon its cost and elemental calcium content, which will vary according
to the type of calcium salt employed (Table 7). In our
clinical practice we use a calcium supplement in solution, composed of calcium
gluconate and calcium lactobionate, and whose elemental calcium content is 216
mg/10 ml.

The elimination
of cow's milk and cow's milk by-products is a risk factor for low calcium intake
since these foods are the main sources of calcium in food. Observations have
been made of inadequate bone mineralization in children subjected to these elimination
diets for prolonged periods.8,10

The anthropometric
assessment of the patients on cow's milk and cow's milk by-products free diets
(Tables 1 and 2),
when compared with that for the control group, presented lower mean z scores
for weight/age, weight/stature and stature/age. At our health service, research
has shown that children with constipation associated with intolerance of cow's
milk presented lower z scores for weight/age, weight/stature and stature/age
than did children with constipation who were shown not to have cow's milk intolerance
following either an elimination diet or a challenge test.29,30 The
subset with constipation and confirmed intolerance to cow's milk protein, acquire
a special interest in the sense that they do not exhibit symptoms such as vomiting,
diarrhea or evidence of intestinal malabsorption which could explain the pondero-statural
deficiencies. Other studies have demonstrated reductions in indices for stature/age3,4,31,32
and weight/stature31 in children with food allergies.

Studies of the
nutritional status of children on elimination diets are scarce, with some observations
suggesting nutritional prejudice, without, however, clearly defining the pathophysiologic
mechanisms involved. Inadequate nutrient intake may have influenced the nutritional
status of the children assessed in our study, but other authors have not found
associations between nutritional status and food consumption.3,4,31
Allergic inflammation that is maintained throughout the elimination diet, whether
by continued contact with the allergen resulting from noncompliance with the
diet or by an allergic reaction to hypoallergenic formula can cause malabsorption
and nutrient loss, impacting on growth.31 If the nutrient loss hypothesis
is assumed to be true, current nutritional recommendations may be insufficient
to guarantee the adequate nutritional status of allergic children,3
in particular those with atopic dermatitis.11,32. Further studies
into this subject are necessary in order to provide more information which would
allow greater security in the dietary guidance of patients with cow's milk allergies
on elimination diets.

Concluding, in
this experiment it was found that children on cow's milk and cow's milk by-products
free diets presented reduced calcium and phosphorous intake when compared with
recommended standards and also when compared with children on normal diets.
The same was true of energy intake, which factor may contribute to the nutritional
deficit detected. Our findings reinforce the need to monitor the nutrient intake
and nutritional status of children put onto diets free from cow's milk and cow's
milk by-products in order to avoid nutrient deficiencies during the elimination
diet.

Acknowledgements

We are grateful
to the staff at the Serviço de Saúde do Jardim Santo Eduardo
in the municipality of Embú and to Professors from the Programa de
Integração Docente Assistencial, for their help. Also to the
Conselho Nacional de Desenvolvimento Científico e Tecnológico
(CNPq).